Aerosol Pollution Over The Largest Cities Worldwide

So many cities nowadays are plagued by aerosol pollution. Notorious PM 2.5 particles are inhaled by our lungs to stay there forever. Here is a global lookup map for quick glance on Aerosol Optical Depth (AOD) distribution across the most populated cities. Meaningful trends are included as well. Spoiler: We are getting better now as aerosol pollution has been decreasing since 2003 in most regions (except South Asia though).
For those who concern, data acknowledgments:
Source: MERRA Aerosol Reanalysis
Authors: Provencel et al., 2017
Data link: doi:10.1016/j.uclim.2017.04.001